São Paulo-based T4U and shareholder D Dots Investments BV plan to sell an undetermined number of common shares in a primary and secondary offering, according to a prospectus on Monday. No details such as the IPO’s potential size or the suggested price tag were included in the prospectus.

T4U, which is controlled by Israel’s Fishman Group, hired Bank of America Merrill Lynch, Itaú BBA SA, UBS AG and Citigroup Inc to handle the transaction. No timetable for the transaction was disclosed.

The IPO plan, the first to be filed in Brazil in about a year, comes at a time when tower operators such as American Tower Corp expand in Brazil. Mobile phone operators are disposing of their towers to instead lease them as a way to preserve cash and protect profits in a flagging economy.

Prospects for Brazil’s equity markets and stock offerings have been gloomy this year, partly because of political uncertainty related to the October presidential election, bankers and investors say.

Stung by a string of deals in recent years that failed to deliver the promised returns, investors have become especially cautious in Brazil. About 40 of 117 IPOs priced since 2005 yielded returns above the benchmark CDI interbank lending rate, with the remainder losing in average half the amount initially invested, according to Thomson Reuters data.

Despite the adverse outlook, equity investors still keep a watchful eye on Brazil because the country’s stock market is bigger, more liquid and more diverse than those in the rest of the region, bankers said. (Additional reporting by Aluísio Alves in São Paulo; Editing by Tom Brown)